[feat] implements service

src/main/java/org/hankki/hankkiserver/api/favorite/service/FavoriteFinder.java

@@ -0,0 +1,19 @@
+package org.hankki.hankkiserver.api.favorite.service;
+
+import lombok.RequiredArgsConstructor;
+import org.hankki.hankkiserver.common.code.FavoriteErrorCode;
+import org.hankki.hankkiserver.common.exception.NotFoundException;
+import org.hankki.hankkiserver.domain.favorite.model.Favorite;
+import org.hankki.hankkiserver.domain.favorite.repository.FavoriteRepository;
+import org.springframework.stereotype.Component;
+
+@Component
+@RequiredArgsConstructor
+public class FavoriteFinder {
+
+  private final FavoriteRepository favoriteRepository;
+
+  public Favorite findById(final long id) {
+    return favoriteRepository.findById(id).orElseThrow(() -> new NotFoundException(FavoriteErrorCode.FAVORITE_NOT_FOUND));
+  }
+}

src/main/java/org/hankki/hankkiserver/api/favorite/service/FavoriteQueryService.java

@@ -0,0 +1,26 @@
+package org.hankki.hankkiserver.api.favorite.service;
+
+import java.util.List;
+import lombok.RequiredArgsConstructor;
+import org.hankki.hankkiserver.api.favorite.service.response.FavoriteFindResponse;
+import org.hankki.hankkiserver.domain.favorite.model.Favorite;
+import org.hankki.hankkiserver.domain.favoritestore.model.FavoriteStore;
+import org.hankki.hankkiserver.domain.store.model.Store;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+@Service
+@RequiredArgsConstructor
+public class FavoriteQueryService {
+
+  private final FavoriteFinder favoriteFinder;
+
+  @Transactional(readOnly = true)
+  public FavoriteFindResponse findFavorite(final long id) {
+
+    Favorite favorite = favoriteFinder.findById(id);
+    List<Store> stores = favorite.getFavoriteStores().stream().map(FavoriteStore::getStore).toList();
+
+    return FavoriteFindResponse.of(favorite, stores);
+  }
+}